Volcanic ash has short- and long-term impacts on the environment and also poses severe hazards to human health, infrastructure, and aviation. Hence, investigating its life cycle from generation to preservation in the geologic record is important to our understanding of eruption hazards and broader interactions with the climate, environment and society. This session brings together interdisciplinary studies on ash-producing eruptions, from particle-scale interactions to global-scale transport, remote sensing of volcanic emissions, numerical modeling of plume dynamics, heterogeneous gas/aerosol-ash interactions, forecasting of airborne concentrations and hazards, and the long-ranging direct and indirect impacts of ash on the atmosphere, hydrosphere, ecosystems, agriculture and human health. We welcome perspectives from volcanology, atmospheric sciences, geochemistry, geophysics, biogeochemistry, palaeoecology, applied tephrochronology and archaeology.